Imaging scanner with light source and pivoting mirror in lid

ABSTRACT

An apparatus providing the capability to scan media at different resolutions is presented. The apparatus comprises an image area which is disposed between scanner lid and a scanner base, the lid is pivotally attached to the base to provide easy access to the image area. A light source resides within the scanner lid. Two separate light paths are provided, the first light path is reflected off opaque targets, through the lid before entering the base and onto an array of photosensitive devices. The second light path is passed through transparent media, into the base and onto the array. First and second focusing lenses are provided, each for a light path. The focusing lenses provide two separate magnifications which yield two separate resolutions.

This is a divisional of application Ser. No. 08/551,220, now U.S. Pat.5,710,425 filed on Oct. 31, 1995.

FIELD OF THE INVENTION

The present invention relates generally to optical scanners and moreparticularly to a scanner which can scan media at different resolutions.

BACKGROUND OF THE INVENTION

An optical scanner is used to generate machine-readable data which isrepresentative of a scanned object such as a document or photograph.This is typically accomplished by employing a controlled light sourcelocated within the base of the scanner. The light source is reflectedoff the surface of a document and back onto an array of photosensitivedevices which convert the light intensity into an electronic signal.Other scanner configurations include transmitting the light sourcethrough a transparent document, and then onto the array ofphotosensitive devices. The intensity of the light source is controlled,via a closed loop or an open loop, by utilizing calibration circuitrylocated within the scanner base.

Optical scanners and various components used within such scanners aredisclosed in U.S. Pat. No. 4,926,041 for OPTICAL SCANNER of David W.Boyd; U.S. Pat. No. 4,937,682 for METHOD AND APPARATUS FOR PROVIDINGCONTRAST/INTENSITY CONTROL IN A DOCUMENT SCANNER of Dan L. Dalton; U.S.Pat. No. 5,019,703 for OPTICAL SCANNER WITH MIRROR MOUNTED OCCLUDINGAPERTURE OR FILTER of David W. Boyd and John S. Deutschbein; and U.S.Pat. No. 5,038,028 for OPTICAL SCANNER APERTURE AND LIGHT SOURCEASSEMBLY of David W. Boyd and C. William Elder, Jr.

SUMMARY OF THE INVENTION

The present invention provides a scanner which scans media at differentresolutions. The scanner provides more than one light path with eachlight path having a different lens reduction ratio. In a preferredembodiment, the scanner comprises at least two lenses and a singlephotodetector array. The present scanner has at least two scanningmodes, one for transparencies and another for reflective, or opaque,objects.

An infeed lever moves mechanical components to allow selected media-typeto be inserted. This lever prevents media-types other than the selectedtype from being inserted. Additionally, the proper infeed speed for theselected media-type is determined by the infeed lever.

In a preferred embodiment, the scanner has first and second light paths,the first light path reflects off opaque targets, the second light pathpasses through transparent targets. The first light path passes througha first focusing lens which has a characteristic first magnification.The second light path passes through a second focusing lens which has acharacteristic second magnification. Both light paths are processed bythe same photodetector array. In a preferred embodiment the first andsecond magnifications are different.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1a and 1b show a block diagram of an exposed side view of anoptical scanner according to the present invention.

FIG. 2 shows a block diagram of a front view of the optical scanner.

FIG. 3 shows a block diagram of the control block according to thepresent invention.

FIG. 4 shows an exploded view of the mechanical components forfacilitating the scanning of multiple media.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1a and lb illustrate an optical scanner 100 of a type adapted toproduce machine readable data representative of a color image of anobject which is scanned. The machine readable data produced by thescanner 100 is adapted to be received and used by a digital computer ina conventional manner, for example, the data may be stored on a computermemory device or may be used to produce a color display of the object ona CRT or a color print.

FIGS. 1a and lb show a block diagram of a side view of the opticalscanner according to the present invention. Scanner 100 has a scannerbase 105 and a scanner lid 110. The lid 110 is attached to the base 105via a hinge (not shown) such that the lid 110 can pivot about a centeraxis of the hinge; this permits easy access to the image area (i.e.,that area disposed between the base 105 and the lid 110). Thehingeably-attached lid 110 ensures manual access to any target media inthe image area. A target medium 115 is disposed between firsttransparent platen 120 and second transparent platen 121 in the imagearea.

A lamp 125 projects a narrow line of light off a pivoting illuminationmirror 175, through the first platen 120 and onto the surface of thetarget 115. If the target 115 is opaque, as in the case of a document orphotograph, the pivoting illumination mirror 175 pivots into a verticalconfiguration to allow the light (illustrated by light path 130) to bereflected off the surface of the target 115, onto mirrors 131 and 132.The pivoting illumination mirror 175 is supported by mirror posts aswill be discussed below in FIG. 4. The light is then reflected offmirror 132, through apertures 135 and onto mirror 133. These mirrors131,132,133 reflect the light through a first focusing lens 134 ontomirror 150. The light is then reflected onto photodetector array 155. Ina preferred embodiment, the target 115 moves past a stationary lamp 125via drive roller 172 and idlers 170,171 for detection by thephotodetector array 155.

Photodetector array 155 converts light intensity into an electricalsignal for an internal controller 160 which, among other things,controls the power to the lamp 125, and adjusts in accordance with thephoto-detector electrical signal. In a preferred embodiment, thephotodetector array 155 comprises charged-coupled devices (CCDs). Inanother preferred embodiment, the CCDs are capable of processing 2700pixels. The internal controller 160 may send image data to amicroprocessor-based system, including a computer or a printer, via link161. In a preferred embodiment, the link 161 is compatible with the SCIbus protocol (akin to RS-232). Other bus protocols, such as SCSI andHPIB could be used without departing from the scope of the presentinvention. The computer, or other device, can also send commands to theinternal controller 160 via link 161.

If the target 115 is transparent, as in the case of a 35 mm slide ornegative strip, the light (illustrated by light path 140) is reflectedoff the pivoting illumination mirror 175 (configured in an angledconfiguration as shown), passed through the first platen 120, throughthe transparent target 115, through the second platen 121 and ontomirror 141. Mirror 141 then reflects the light through a second focusinglens 142 onto mirror 150. This light is then reflected onto thephotodetector array 155 for processing. In a preferred embodiment, themagnification of the first focusing lens 134 is different from themagnification of the second lens 142. In another preferred embodiment,the magnification of the first focusing lens is 0.165X and themagnification of the second focusing lens 142 is 0.7559X.

An obstructor 180 is disposed below the mirror 150. Obstructor 180comprises first and second blocking panels 181,182. Based upon a controlsignal sent from an infeed lever control (see FIG. 2), one of thefocused light paths will be obstructed. If the control signal indicatesthat a transparent target is to be scanned, obstructor 180 positionsblocking panel 181 in the path of the focused opaque light path 130'. Ifthe control signal indicates that an opaque target is to be scanned,obstructor 180 positions blocking panel 182 in the path of the focusedtransparency light path 140'.

A feature of the present invention is the dual light paths 130,140. Theresolutions provided by these separate light paths are dependent on thetarget being scanned. Typically, there is less information present on aphotograph than on a slide. In a preferred embodiment, the opaque lightpath 130 provides a resolution to 300 dots per inch (dpi) while thetransparency light path 140 provides a resolution to 2400 dpi.

FIG. 2 shows a block diagram of a front view of the optical scanneraccording to the present invention. The scanner 100 provides an infeedlever control 210 which determines which selectable media-type can beinserted. An infeed lever (not shown) moves mechanical components basedupon the control signal sent by control 210 to allow the selectedmedia-type to be inserted into the scanner 100. At the same time,control 210 prevents other, non-selected, media-types from entering thescanner 100. A feature of the present invention is that scanner 100 ismechanically reconfigurable to permit and/or deny access to the scanningmechanism (i.e., the light paths, mirrors, photodetector array andcontroller). Once the end-user of scanner 100 selects which media-typeis to be scanned, the scanner 100 presents the requisite slot for theend-user to enter that selected media-type.

Additionally, control 210 sets the speed with which the selectedmedia-type is entered and sends a control signal to the obstructor (item180 in FIG. 1b) to block the light path of the nonselected media-type.Scanner 100 accepts three separate media-types through an input portthat has three different configurations 220,230,240. In a preferredembodiment, scanner 100 accepts a print photograph (item 220) up to thedimensions of 5"×7" (127 mm by 177.8 mm), a 35 mm slide (item 230), anda 35 mm negative strip (item 240). In a preferred embodiment, the speedwith which a print photograph is entered is faster than with respect toa 35 mm slide or 35 mm negative strip. In another preferred embodiment,a print photograph is scanned at 0.003 inches/second (0.076 mm/sec)while a 35 mm slide or negative strip is scanned at 0.00042inches/second (0.01058 mm/sec).

FIG. 3 shows a block diagram of the control block. The control block 160is centered around a microcontroller 302. The microcontroller 302 maybe, for example, a 68HC05 microcontroller available from Motorola, Inc.,Schaumburg, Ill. The microcontroller 302 receives commands from thescanner via the serial communications link 161. Commands sent from thescanner include, among other things, turning on the lamp, change lightintensity, and report status.

The microcontroller 302 drives a digital-to-analog converter (DAC) 304and a lamp driver 306. One output of the DAC 304 is connected to thelamp driver 306, while a second DAC output is connected to a comparator312. The comparator 312 also receives input from a photodiode whichmeasures the light intensity of the lamp 308 and converts it to ananalog signal. This signal is then supplied to the comparator 312 asfeedback to maintain the light intensity of the lamp 308 at a constantlevel.

FIG. 4 shows an exploded view of the mechanical assembly forfacilitating the scanning of multiple media. The mechanical assembly islocated in the scanner base 105 and comprises a negative cap 440, acarriage 420, and a gill 410. The gill 410 comprises a front face 411, aslide base 412, a print ledge 413 and a cam 414. The negative cap 440comprises an aperture rise 441, at least two posts 442 and a top portion443. The carriage 420 comprises an aperture 421, first and secondnegative guide plates 422,423, a plurality of roller apertures 424,negative guide sides 426, a plurality of guides 427 and at least twomirror support posts 431. The plurality of guides 427 support the targetmedia that is placed in the scanner. The at least two mirror supportposts 431 support the pivoting illumination mirror (item 175 in FIG.1a), the mirror pivoting as the mechanical assembly moves upward anddownward with respect to the control signal from control 210. In apreferred embodiment, the negative cap 440, the carriage 420 and thegill 440 are all formed of plastic, although other materials could beused without departing from the scope of the present invention.

Depending on which media-type was selected (via control 210), themechanical assembly moves to permit the selected media-type to enter thescanner and, at the same time, prohibit the nonselected media-types fromentering. In a preferred embodiment, there are three media-types: printphotograph, 35 mm slide, and 35 mm negative strip.

If the print photograph media-type has been selected, gill 410 is drivenby the cam 414 downward in relation to carriage 420 so that the printphotograph can be fed along print ledge 413. The drive roller (item 172in FIG. 1b), which is positioned in the plurality of roller apertures424, moves the print photograph along through the scanner 100. Afterscanning the print photograph, the drive roller reverses direction tosend the print photograph back out from the scanner 100. In a preferredembodiment, the drive roller is a single roller having a plurality oflarge diameter sections, corresponding to the plurality of rollerapertures 424, interconnected by a plurality of small diameter sections.Additionally, the drive roller has two internal sections that arepositioned on the inside of the negative guide sides 426. In a preferredembodiment, the two internal sections have the same diameter as thelarge diameter sections and each has a width sufficiently thin enough toensure that light path 140 (see FIG. 1a) is not hindered as it passesthrough the transparent media, through aperture 421 and onto theinternal mechanisms of the scanner. In another preferred embodiment, thedrive roller is comprised of a plurality of separate rollersinterconnected via an roller axle.

If the 35 mm slide media-type has been selected, gill 410 is driven bythe cam 414 upward relative to the carriage 420 to permit the 35 mmslide to be positioned on the slide base 412 before the internalsections of the drive roller moves the slide into, and then out from,the scanner. If the 35 mm negative strip media-type is selected, gill410 is driven by the cam 414 further upward relative to the carriage 420and the negative cap 440. First and second negative guide plates 422,423, in conjunction with the negative guide sides 426 ensure that properalignment of the negative strip is achieved across aperture 421. In apreferred embodiment, the negative guide plates 422,423 are at least 35millimeters apart.

A feature of the present invention is that the same mechanical assemblyis used to move different media-types across the scanning aperture. Thatis, the roller, carriage 420 and gill 410 are designed to transportprint photographs up to a size of 5"×7" (127 mm ×177.8 mm), 35 mm slidesand 35 mm negative strips.

While the present invention has been illustrated and described inconnection with the preferred embodiment, it is not to be limited to theparticular structure shown. It should be understood by those skilled inthe art that various changes and modifications may be made within thepurview of the appended claims without departing from the spirit andscope of the invention in its broader aspects. For example, a moveablelens can be provided in place of the first and second focusing lenses(items 134 and 142 in FIG. 1a). In this configuration, the moveable lenscan be moved from a first position in light path 130 through to a Nthposition in light path 140 using an actuator. N positions throughout thepath of the moveable lens can be used to provide a "zoom" for infinitelyvariable resolutions.

We claim:
 1. A scanner comprising:a scanner base; a scanner lid attachedto the scanner base; an image area disposed between the scanner base andthe scanner lid; first and second light paths, the first light pathreflects off the image area, the second light path passes through theimage area; and a pivoting mirror located in the scanner lid, thepivoting mirror pivots between at least two positions, the second lightpath reflects off of the pivoting mirror through the image area.
 2. Thescanner of claim 1 further comprising first and second focusing lenses,the first focusing lens is located in the first light path, the secondfocusing lens is located in the second light path.